Gas supply system

Abstract

The gas supply system of this invention is furnished with a cylinder apparatus having a pneumatic valve that supplies process gas to a process chamber, and a solenoid valve that opens or closes said pneumatic valve by supplying or stopping the flow of valve actuating gas to said pneumatic valve; and a gas supply control apparatus that controls the actuation of the solenoid valve. In addition, said gas supply control apparatus comprises a main controller that controls the actuation of said solenoid valve during normal operation, and a sub-controller that senses an abnormal state of said main controller and if an abnormality is sensed, controls the actuation of said solenoid valve instead of said main controller.

We claim: 
     
       1. A gas supply system, comprising:
 a cylinder apparatus having one or more pneumatic valves that controls the supply of process gas to a process chamber, and one or more solenoid valves that opens or closes said pneumatic valve by supplying or stopping the flow of valve actuating gas to said pneumatic valve; and 
 a gas supply control apparatus that controls the operation of the one or more solenoid valves;
 wherein said gas supply control apparatus comprises:
 a main controller that controls the actuation of the one or more solenoid valves during normal operation; 
 a sub-controller that senses an abnormal state of said main controller and upon sensing an abnormality, controls the actuation of said one or more solenoid valves instead of the main controller;
 wherein said main controller and said sub-controller share digital sensing information through digital interfacing directly with each other, and the main controller and the sub-controller additionally share analog sensing information through analog interfacing directly with each other; 
 
 a monitoring system and a communication line;
 wherein said monitoring system selectively communicates with said main controller and sub-controller to continuously monitor the process gas supply status; and 
 
 a changeover switch for interconnecting the main controller with the monitoring system through the communication line in the normal state and for interconnecting the sub-controller and the monitoring system through the communication line when the abnormality is detected, separately from the digital and analog interfacing between the main controller and the sub-controller. 
 
 
 
     
     
       2. The gas supply system according to  claim 1 , wherein said digital sensing information comprises at least one selected from the group consisting of:
 flame sensing information that is input from a flame sensing optical sensor, high-temperature sensing information that is input from a high-temperature sensor, and gas leakage sensing information that is input from a gas leakage sensor;
 wherein said flame sensing optical sensor, said high temperature sensor, and said gas leakage sensor are mounted in the cylinder apparatus. 
 
 
     
     
       3. The gas supply system according to any of  claim 1 , wherein said analog sensing information comprises at least one selected from the group consisting of:
 gas supply pressure sensing information that is input from one or more pressure sensors, cylinder weight sensing information that is input from one or more weight sensors, and process gas temperature information that is input from one or more process gas temperature sensors; and 
 wherein said one or more pressure sensors, and one or more temperature sensors and one or more weight sensors, if present, are mounted in the cylinder apparatus. 
 
     
     
       4. The gas supply system according to  claim 1 , wherein said cylinder apparatus further comprises one or more heaters and one or more process gas temperature sensors and said main controller controls the actuation of the one or more heaters to prevent liquifying of the process gas based on the heating temperature sensing information from said one or more process gas temperature sensors, and wherein when said abnormality sensing occurs, said sub-controller controls actuation of the one or more heaters based on said heating temperature sensing information, in order to prevent liquefying of the process gas. 
     
     
       5. The gas supply system according to  claim 1 , wherein said digital sensing information comprises at least two selected from the group consisting of:
 flame sensing information that is input from a flame sensing optical sensor, high-temperature sensing information that is input from a high-temperature sensor, and gas leakage sensing information that is input from a gas leakage sensor. 
 
     
     
       6. The gas supply system according to  claim 1 , wherein said analog sensing information comprises at least two selected from the group consisting of:
 gas supply pressure sensing information that is input from one or more pressure sensors, cylinder weight sensing information that is input from one or more weight sensors, and process gas temperature information that is input from one or more process gas temperature sensors. 
 
     
     
       7. The gas supply system according to  claim 1 , wherein said monitoring system communicates with a central control room by electrical communication between the monitoring system and the control room. 
     
     
       8. A method of controlling a gas supply system comprising one or more pneumatic valves that control the supply of process gas to a process chamber, and one or more solenoid valves that open or close each of said pneumatic valves by supplying or stopping the flow of valve actuating gas to each of said pneumatic valves; and a gas supply control apparatus that controls the operation of the one or more solenoid valves; wherein said gas supply control apparatus further comprises:
 a main controller that controls the actuation of the one or more solenoid valves during normal operation; 
 a sub-controller that senses an abnormal state of said main controller and upon sensing an abnormality, controls the actuation of said one or more solenoid valves instead of the main controller;
 wherein said main controller and said sub-controller share digital sensing information through digital interfacing directly with each other, and the main controller and the sub-controller additionally share analog sensing information through analog interfacing directly with each other; 
 
 a monitoring system and a communication line;
 wherein said monitoring system selectively communicates with said main controller and sub-controller to continuously monitor the process gas supply status; and 
 
 a changeover switch for interconnecting the main controller with the monitoring system through the communication line in the normal state and for interconnecting the sub-controller and the monitoring system through the communication line when the abnormality is detected, separately from the digital and analog interfacing between the main controller and the sub-controller. 
 said method comprising the steps of:
 sharing digital, analog, or digital and analog, sensing information through digital, analog, or digital and analog, interfacing between said main controller and said sub-controller; and 
 switching control of said gas supply system to said sub-controller that senses an abnormal state of said main controller; wherein said sub-controller controls the actuation of said one or more solenoid valves instead of the main controller. 
 
 
     
     
       9. The method of  claim 8  further comprising the step of: maintaining the valve position of the one or more solenoid valves upon switching the control to the sub-controller. 
     
     
       10. The method of  claim 8 , further comprising the step of: activating one or more heaters by the sub-controller in response to process gas temperature information. 
     
     
       11. The method of  claim 8 , further comprising the step of: communicating a process gas supply status to a central control room. 
     
     
       12. The method of  claim 8 , further comprising the step of: communicating an emergency to a central control room when sensing information indicates that an unsafe level for any of the sensed information has been sensed. 
     
     
       13. The method of  claim 8 , further comprising the step of: shutting down the gas supply apparatus when any of the sensing information indicates that an unsafe level for any of the sensed information has been sensed.